You probably know that animals are broken up into groups such as mammals, reptiles, birds, amphibians, invertebrates, and insects. You also probably know that some animals are more likely to lay eggs (such as reptiles and birds) while others are more likely to give birth to live young (like mammals). So where do armadillos fall in this division?
Do armadillos lay eggs?
Armadillos do not lay eggs. Instead, armadillos give birth to live babies. This is the norm for the vast majority of mammals. Even though armadillos have an armored appearance that makes them look almost reptilian, they are in fact mammals.
After armadillos mate, baby armadillos develop from the same fertilized egg inside of their mother. Female armadillos will then give birth to their offspring live. Usually, a female will carry one to three babies at a time. The exception to this is the Dasypus armadillo – a female Dasypus armadillo can carry up to twelve infants at a time!
These young armadillos are called “pups.” A female armadillo is usually pregnant for three to five months before giving birth to her pups in a burrow. The burrow that these mothers will use can be up to fifteen feet wide.
Pups will be fed milk for only the first two to four months of their life and then they are completely weaned off of it. By the time they are between nine and twelve months old, they will be completely mature and be ready to have pups of their own. Armadillos can live to be up to thirty years old.
Another interesting fact about baby armadillos is that the nine-banded armadillo will have identical quadruplets every single time she is pregnant! This is because once her egg is fertilized, the egg will break up into four completely identical embryos so when she gives birth, she has four identical babies.
Scientists are unsure why that happens because most animals survive by having genetic diversity in their offspring, as opposed to the nine-banded armadillo who produces four clones every pregnancy.
Additionally, apart from making milk for their babies and feeding them, mother armadillos are not overly attentive parents. A female armadillo’s most important job is to give her pups the nutrients they need to be able to grow a strong carapace, which is the shell that covers and protects the body of an armadillo.
She must make sure that the pups get plenty of calcium and phosphorus, as well as other nutrients that they need to grow strong and she does this by eating a diet of mostly insects. But besides that, she does not do much to take care of her young pups. Father armadillos are even less involved in their pups’ lives.
Do any mammals lay eggs?
There are only two living mammals in the world that lay eggs. These mammals are the spiny anteater (which are also known as echidnas) and the platypus. These mammals have a lower body temperature than most mammals. In fact, their body temperature is much closer to that of a reptile.
What unites these egg-laying mammals from mammals that give birth to their young live, is that all mammals feed their young milk. Mammals are the only members of the animal kingdom that produce milk for their babies to drink.
Mammals that lay eggs are called monotremes and they share the other qualities that set mammals apart such as a body covered in hair, the presence of sweat glands, the presence of three middle ear bones, and the presences of a part of the brain called the neocortex (which is the part of the brain that makes mammals more highly developed than the other types of animals in the world).
Scientists believe that monotremes lay eggs because of where they live. You see, monotremes are related to marsupials (which are mammals that have pouches such as kangaroos, koalas, and possums). All marsupials live solely on land, whereas the two monotremes live partly in the water and partly on land. These animals may have been able to survive so long because they were able to adapt to water and lay eggs.